Re: [RFC v3 6/8] wifi: mac80211: extend ifcomb check functions for multi-radio

[Karthikeyan Periyasamy <quic_periyasa@xxxxxxxxxxx>]

On 6/7/2024 3:52 PM, Felix Fietkau wrote:
> On 07.06.24 12:07, Karthikeyan Periyasamy wrote:
> > On 6/6/2024 11:37 PM, Felix Fietkau wrote:
> > > Add support for counting global and per-radio max/current number of
> > > channels, as well as checking radio-specific interface combinations.
> > >
> > > Signed-off-by: Felix Fietkau <nbd@xxxxxxxx>
> > > ---
> > >   net/mac80211/cfg.c         |   7 +-
> > >   net/mac80211/chan.c        |  17 +++--
> > >   net/mac80211/ibss.c        |   2 +-
> > >   net/mac80211/ieee80211_i.h |   6 +-
> > >   net/mac80211/iface.c       |   2 +-
> > >   net/mac80211/util.c        | 131 
> > > +++++++++++++++++++++++++++-----------
> > >   6 files changed, 116 insertions(+), 49 deletions(-)
> > >
> > > diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
> > > index 62119e957cd8..950b7b72f0b8 100644
> > > --- a/net/mac80211/cfg.c
> > > +++ b/net/mac80211/cfg.c
> > > @@ -263,7 +263,7 @@ static int ieee80211_start_p2p_device(struct 
> > > wiphy *wiphy,
> > >       lockdep_assert_wiphy(sdata->local->hw.wiphy);
> > > -    ret = ieee80211_check_combinations(sdata, NULL, 0, 0);
> > > +    ret = ieee80211_check_combinations(sdata, NULL, 0, 0, -1);
> > >       if (ret < 0)
> > >           return ret;
> > > @@ -285,7 +285,7 @@ static int ieee80211_start_nan(struct wiphy *wiphy,
> > >       lockdep_assert_wiphy(sdata->local->hw.wiphy);
> > > -    ret = ieee80211_check_combinations(sdata, NULL, 0, 0);
> > > +    ret = ieee80211_check_combinations(sdata, NULL, 0, 0, -1);
> > >       if (ret < 0)
> > >           return ret;
> > > @@ -4001,7 +4001,7 @@ __ieee80211_channel_switch(struct wiphy *wiphy, 
> > > struct net_device *dev,
> > >           goto out;
> > >       /* if reservation is invalid then this will fail */
> > > -    err = ieee80211_check_combinations(sdata, NULL, chanctx->mode, 0);
> > > +    err = ieee80211_check_combinations(sdata, NULL, chanctx->mode, 
> > > 0, -1);
> >
> > Once we reach the global limit, all the -1 passing caller get fail
> > becuase the iface check param (existing and new) is validated against
> > the global limit. since global limt as a sort of union of all per-radio
> > limits.
> >
> > Ex:
> > Global iface = 6 (Radio iface 2GHz:4, 5GHz:4, 6GHz:6)
> >
> >
> > So far 6 iface created (Radio iface 2GHz:2, 5GHz:3, 6GHz:1)
> >
> > In this case, new iface creation get fail because caller uses
> > ieee80211_check_combinations() with -1 as radio idx, so it checked
> > against global limit
>
> Use the sum of the number of interfaces from each radio instead of the 
> maximum.

Oh, then legacy user have misconception of the global interfaces 
advertised and try to fail for the allowed limits.

--
Karthikeyan Periyasamy
--
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